Lead acid batteries are a fundamental staple of our modern electrical society, these batteries are found in almost every aspect of our daily lives whether we realize it or not. Lead acid batteries are used in transportation, heavy equipment, telecommunications, computer networking, backup power supplies, alternative energy solutions (a.k.a. solar, wind, and small hydro turbine solutions).
As the need to store and have electrical energy ready as demand increases, so does the importance of the battery. Lead acid batteries have been the workhorse of this need for more than a century. One of the problems that arises from the use of these batteries is the sulfation of the lead plates within the battery that limit and ultimately render useless the energy obtainable from them.
During use of the battery the sulfuric acid chemical solution electrolyte deposits sulfide crystals on the plates of the battery. As the crystals grow the battery's output declines sharply, as less and less surface area of the lead plate has the ability to interact with the electrolyte solution.
The conventional solution to this build up is to do what is called an equalization charge. This charge is really a controlled over charge of the battery. High amperage and a voltage capable of putting the battery into reverse or charge mode is applied to the battery. This high amperage charging leads to internal heating, which leads to less conduction, which in turn leads to more heating. If not carefully controlled, the battery can enter a thermal runaway effect that overheats the battery and causes excessive off gassing of the electrolyte solution. This situation usually irreversibly damages the battery.
Current charging systems basically fall into one of two categories: 1. Standard high amperage regulated voltage charger with trickle charge capacity; 2. Low amperage pulse charge systems with timed charging.
Standard high amperage and trickle chargers apply a regulated voltage of sufficient value to put the battery into charge mode and a moderate to high current level to charge the battery. This charge may remove a small amount of the sulfate crystal growth, but it still has the disadvantage of heating the battery, and cannot remove the crystal growth effectively enough to keep the battery from sulfating.
Pulse charging attempts to apply a low current voltage with a resonate frequency square wave to the battery in order to induce desulfation without overheating the battery. These charging systems tout the ability to keep a battery from heavy sulfation through the use of a low amperage continuous pulse charge. This system has the distinct disadvantage of having to constantly keep the battery on the charger in order to keep the sulfation process at bay.